1. Technical Field
The present invention relates to a projector.
2. Related Art
A projector which includes an electro-optic device for modulating light emitted from a light source, and a projection lens for projecting the modulated light is known. In the field of this projector, such a type which has a lens shift mechanism capable of shifting a projected image without change of the posture of the projector by a user has been proposed (for example, see JP-A-2007-33591).
The lens shift mechanism disclosed in JP-A-2007-33591 includes a frame member for supporting the projection lens, a pair of guide shafts disposed on both sides of the projection lens, a base frame fixed to the inside of the projector, and a shift mechanism unit.
The frame member has sliders into which the pair of the guide shafts are inserted, and a connection frame provided between one of the sliders and the projection lens. The connection frame has a nut. The shift mechanism unit has a function of shifting the frame member, and includes a screw engaging with the nut, a rotation transmission gear mechanism, and a driving motor. The rotation transmission gear mechanism has a worm gear, a spur gear or the like, and is disposed on the base frame. According to this structure, the screw rotates in accordance with the drive of the motor transmitted via the rotation transmission gear mechanism, whereupon the frame member engaging with the screw rises or descends along the guide shafts. As a result, the projection lens supported by the frame member shifts with the frame member.
According to the projector disclosed in JP-A-2007-33591, the sliders and the connection frame are disposed on an area in the vicinity of the side of the projection lens. In addition, as shown in the figure, the components such as the motor are disposed in such positions as to project from the base frame. In this case, the size of the lens shift mechanism increases. Moreover, while JP-A-2007-33591 shows an embodiment in which the projection lens is shifted in the vertical direction by using the lens shift mechanism, the size of the projector further increases in such a case where the projection lens is shifted in the horizontal direction as well as in the vertical direction.